The canonical form a registry hashes to

Renders the declaration as a sorted, escaped, line-oriented text form and returns its lines. registry_digest() hashes exactly these bytes, so a digest is never a black box: two registries that disagree can be diffed on the text that produced the disagreement.

Usage

registry_manifest(registry)

Arguments

registry: A registry() object.

Value

A character vector of lines, classed getaca_manifest.

Details

Hashing the R object directly is not an option. A resource() may carry a processor(), which holds a closure, and a closure digests differently across machines and builds because its environment, bytecode and source references travel with it. A registry declaring a processor would appear to change identity on every machine. The manifest reduces a processor to its id, which is what the declaration actually promises.

Format

The first line names the format version, which moves independently of schema_version because the two change for different reasons: a new field in the stored form need not change how existing fields are rendered.

getaca-manifest 1
package yourpkg
remote https://yourpkg.example.org/registry.rds
key ed25519:9f8a...
auth data.example.org bearer EXAMPLE_TOKEN
  register https://data.example.org/register
current backbone 2026-09
resource backbone 2026-06
  sha256 3f9ac2...
  size 1048576
  license CC-BY-4.0
  doi 10.5281/zenodo.123
  url https://zenodo.org/record/123/backbone-2026-06.parquet
  url https://mirror.example.org/backbone-2026-06.parquet
  upstream release 2026-06
  processor unzip-v2
resource backbone 2026-09
  sha256 b104e7...
  file backbone.parquet
  part 91cc0d... 1048576
    url https://zenodo.org/record/456/backbone-base.bin
  part 4e77a1... 20481
    url https://zenodo.org/record/456/backbone-2026-09.bin
  combiner concat

Resources are sorted by name@version in the C locale, so the same declaration renders identically wherever it is read. URLs keep declaration order, which is load-bearing: mirrors are tried in the order given. Parts keep it for a stronger reason, since the order is the one they are combined in. Signing keys are sorted, since which one signs is a fact about the signature rather than about the declaration. Absent and NA fields are omitted rather than rendered as empty, since a key that is present carries a value by construction.

Rendering an absent field as nothing is what let signing keys join the manifest without a new format version, and then file, part, combiner, auth and doi after them. A registry declaring none of them renders exactly the bytes it always did, so every digest recorded before they existed still identifies the state that produced it.

What is left out

created and policy are not part of the declaration. created says when a state was written and policy supplies a default; neither changes which bytes a name resolves to, and including either would mean an unchanged registry took on a new identity for writing it out again. description is prose, so a typo fix would invalidate a digest already recorded in provenance.

Examples

reg <- registry("demo", list(
  resource("example", "1.0",
           urls = "https://example.org/example-1.0.csv",
           sha256 = strrep("c", 64), license = "CC0-1.0")
))
registry_manifest(reg)